What was found
UNUSUAL ODOR ISOLATED TO THE FLIGHT DECK, AFTER TAKEOFF & DURING ENTIRE TIME EN ROUTE. NO SMOKE JUST A STRONG ODOR AT ALTITUDE. POWERED UP ACFT, RAN ENGS & APU WITH NO ODOR, INSPECTED COCKPIT DISPLAYS NO DEFECTS NOTED. PERFORMED OPERATIONS CHECKS OF DISPLAY FANS, ALL CHECKED GOOD. INSPECTED COCKPIT FLASHLIGHT & FOUND A CHEMICAL BATTERY SMELL COMING FROM FLASHLIGHT. REPLACED TWO EACH FLASHLIGHTS & BATTERIES WITH NEW. OPERATIONS CHECKED IAW AMM 25-60-00. ALL CHECKED GOOD. NO SMELL FROM NEW FLASHLIGHTS AT THIS TIME.